Chance-based contests typically take two forms. In one form, contest prizes may be awarded at the time a contestant plays. The chances of winning are fixed (for example, 100:1). An advantage of this form of awarding chance-based contest prizes is that there typically may be some instant gratification since a contestant may know whether they won or lost at the time of entry.
In another form, contest prizes may be awarded at the end of the contest. The chance of winning depends on the number of prizes, which may typically be fixed, and the number of contestants, which may typically be variable. An advantage of this form of awarding chance-based contest prizes is that the cost to run the contest typically may be known in advance since a known number of prizes typically may be awarded.